jkr@IFI.UIO.NO (06/09/89)
There subject of upgrading the Megafile/SH205 series with other drives or second drives
seems to be of general interest, so here we go:
I'll start off with a little disclaimer, though:
I did this approx. 5 months ago with a SH205, so my memory may be a little weak....:-)
To replace the existing drive on a SH205:
Throw out the old drive,- If you really consider it worth anything you might find it
worthwhile parking it first. Insert the new (and improved) drive in the place of the old one.
If the new drive doesn't have the railings of the old one (for mounting) you might consider
A) getting a new one or B) buying a "torx" screwdriver to rip the mountings off the old one.
Connect all the cables just like they were on the other drive. Remember to check the
device dips on the new drive before inserting it, it should be device 0.
Now this should be all you need to do with you *drive*. The next thing to do is to
look in the WINCAP.SYS file, and adjust the parameters (for some unlikely drive)
so that they match the ones on your new drive. The WINCAP file is an ordinary
text-file, and you'll need to know several things about the new drive, like
number of cylinders, sector per cylinder etc. You might consider doing this
modification to your WINCAP file BEFORE you remove the old disk.
I'm not 100% on the contens of the WINCAP file, since I only looked briefly
at it 5 months ago :-). One thing I DO remember is that it was VERY WELL COMMENTED.
Now, this may (and again, may not) be adequate. Try sending me a little note
at jkr@ifi.uio.no (or f-jkr@ifi.uio.no) if something seems to be unclear.
* Adding a SECOND drive *
WARNING: The power supply in the SH205 and the MEGAFILE series are NOT dimensioned for two
drives. Your milage may vary on this one, due to different power consumptions.
This problem actually only occurs on startup, when both drives need that extra little
'kick' to get going. A German firm called Eickmann has somehow solved this, but I have
yet to open an Eickmann-modified SH205 :-). The problem is the 1.6A 12VDC.
(The drive that's in there already pulls .8 or .9A.
There are two cables that go from the controller to the drive. One is about 40pins wide,
while the other is approx. 28 pins wide. The 40 pin cable should be extended, to make
room for two plugs. In practice this means you'll have to make a new cable.
(Buy 1 meter 40-pin vable + the appropriate connectors). The 40-pin cable should be
a straight-thru affair,- all pins are 1:1 on BOTH connectors.
The second cable is a bit worse: if you look at the connection on the PCB for
the narrowest cable, you'll see that there's another set of solder joints for
a likewise connector,- just behind the existing one. You'll need to install another
PCB-contact in those holes. When you've done that, you'll have to make a duplicate of
the existing (narrow) cable. The duplicate cable should be connected from the (new)
connector on the PCB to the second drive. Remember that the new drive should be device number
1. If the new drive doesn't have device dips, you can re-dip the old one to dev 1.
Now for the VAGUE part: Installing the new drive shouldn't be all that difficult.
The hard-disk SHOULD act like a normal drive when you've done all of the above.
(+ power connectors). To make the drive recognize the new hard-disk you'll have
to short a jumper. This is where my memory fails me...
I know (100% sure) that the jumpers are located in the close vincinity of the fan.
There are 5-7 of them, labeled in alphabetic order. The one that should be shorted
(closed) is NOT among the two rightmost or the two leftmost, but that's all I can remember.
(I don't have the upgraded 205 any more, so I can't look....)
What I DO remember is that I tried ALL of them before finding the right one, and my disk
still lives. Looking from the front of the drive, I'd give number 4 from the left
a try. When you get this right it should only be a problem of getting the format-parameters
right. (I used the ICD driver).
WARNING1: The power supply will most probably NOT tolerate 2 drives.
WARNING2: Remember to get the orientation of the cables correctly.
WARNING3: A 2 drive SH205 can get very hot. Avoid stacking.
WARNING4: The 205 series does NOT support FAST drives. A friend of mine tried a
28ms drive, and it failed gracefully.
DISCLAIMER: I take no responsibility, for anything, not even for this disclaimer.
Kristian Rosenvold, jkr@ifi.uio.no